Director Johannes Roberts has tried his hand at some relatively quirky horror projects (“The Other Side of the Door,” “47 Meters Down”), but with this sequel to Bryan Bertino’s 2008 “The Strangers,” he simply takes a page out of the old slasher movie playbook. “The Strangers: Prey at Night” is in once sense a throwback to movies of the eighties, but it’s gorier and grosser, winding up as an exercise in pure sadism that feels all the more sordid because it’s quite efficiently made.

The targeted victims this time around aren’t a couple enjoying a forbidden tryst on a remote estate, but—befitting the low-rent character of a follow-up that’s been in the works for a decade—a squabbling middle-class family in a trailer park. The parents are Cindy (Christina Hendricks) and Mike (Martin Henderson), who are driving their daughter Kinsey (Bailee Madison) to a boarding school because she’s been acting up with her equally troublesome friends; her older brother, straight-arrow Luke (Louis Pullman) is along for the ride. They plan a stopover at their Uncle Marvin’s trailer home.

For a long stretch early on, the movie concentrates on the problems within the group. Kinsey is constantly surly, chain-smoking (though she doesn’t inhale, Luke notes) and saying spiteful things; the others are understandably irritated. The purpose is presumably to flesh out the characters, but if so the effort goes unrewarded; none of the four develop any real personality. When they arrive at the park, Marvin is gone, leaving behind a note of welcome, and the rest of the place appears deserted except for a strange girl who knocks at the door asking for someone who doesn’t live there.

When Luke and Kinsey go off for a walk, they find a trailer with a badly brutalized corpse inside, and rush to tell their parents. We already know the cause, since a brief prologue has shown a sleeping woman being woken and confronted by the home invader with a sack over his head identified in the credits as the Man in the Mask (Damian Maffei). But as it turns out he has two helpers, Dollface (Emma Bellomy) and Pin-Up Girl (Lea Enslin), both of whom wear plastic masks similar to the one popularized in “V for Vendetta.” And using such tools as hatchets, knives and a battled old pick-up truck, they go after the newcomers, having apparently offed everyone else in the park.

The only matter in the story is the order in which our four potential victims are attacked, whether they survive and if so how, and how far the survivors will get before they’re attacked again. It’s a protracted game of cat and mouse in which, frankly, one’s concern for the fate of the prey, never very high to begin with, grows increasingly weak. The main center of attention in Kinsey, who takes on the Jamie Lee Curtis “Halloween” part of the intrepid damsel who escapes again and again until a final confrontation—or series of confrontations—with the Man in the Mask. (The comparison is particularly apt since Adrian Johnston’s score cribs fairly shamelessly from John Carpenter’s for his holiday-themed classic.)

Before then others in the family haven’t been so lucky, succumbing—or not—in showy run-ins with the killers staged as extravagant set-pieces. The most notable is certainly a struggle in a neon-lit swimming pool that must be in the park’s amusement area (who knew trailer parks had such lavish amenities?) that ends with the blood of a stabbing victim spreading out around the body in the water like a red halo in the blue water. It’s actually a pretty impressive effect, but no more than an effect, since the movie has built up no real interest in the person involved.

This is primarily a director’s movie, and Roberts shows that he knows his way around such basic material, and he works well with cameraman Ryan Samul and editor Martin Brinkler to achieve the desired result in individual scenes. Of the actors, Madison has the greatest amount of screen time, and is adequate though little more; the others go through the expected paces without making any substantial impact.

And for all its blood and gore, the movie doesn’t make much of a splash either. We’ve seen this sort of thing entirely too often in the past to be scared by what goes on here; “Prey at Night” is somewhat less grubby, in purely visual terms, than most of its predecessors, but that only means that the packaging, not the content, is better.

When, in the first picture, one of the intruders was asked why they’d chosen this house to break into, the response was the nonchalant “Because you were home.” This time around, the only words spoken by an intruder come in response to a query about why they’re killing people: “Why not?” It’s that sense of utter nihilism that apparently won the original “Strangers” the attention it got (especially in the ancillary markets), and it continues in this sequel.

But other horror movies have latched onto that attitude over the last decade, and to an ever-increasing degree. The more pertinent fact now is that a director like Roberts would probably answer “Why not?” if asked why he chose to make a movie as pointlessly repulsive as this one, and viewers who plunk down their money to see it would probably have much the same response if queried about why they’d want to see such a thing. In the end it’s what pictures like this say about the current state of our culture that’s the most important aspect of “The Strangers: Prey at Night.”